The present invention relates to industrial processes, and more particularly to apparatus for removing contaminants such as oils from a liquid reservoir, extending the life of a batch of process liquid such as a solvent.
In many industrial processes, a liquid such as a solvent is circulated from a reservoir to a process location such as a cleaning station, from which the liquid is recovered and transported back to the reservoir and reused. A problem with such processes is that the liquid gradually gets contaminated with foreign material such as oils. When the contamination reaches unacceptable levels, the liquid is discarded, and the reservoir is refilled.
The contaminants typically collect in one or more layers within the reservoir. For example, in many cases, a film of oil contamination accumulates at the top of the liquid in the reservoir. In other cases, a layer of liquid or solids collects at the bottom of the reservoir. It is also possible for contamination to accumulate in a layer at a boundary between different liquid components of the reservoir.
Thus there is a need for a way to extend the life of the process liquid by removing at least a substantial portion of the contaminants from the liquid, that is effective with commonly encountered combinations of liquid and contaminant, and that is easy and inexpensive to provide and use.